Nitinol Wire - Material Information

Nitinol, a nickel–titanium (Ni–Ti) shape memory alloy, is one of the most remarkable smart materials due to its ability to return to a pre-defined shape when heated above a certain transformation temperature. With exceptional strength, corrosion resistance, and biocompatibility, Nitinol has found widespread use in biomedical, aerospace, and actuator technologies. Its unique shape memory and superelastic effects arise from a reversible solid–solid phase transformation between the high-temperature austenite and low-temperature martensite phases.

Material Overview

Nitinol crystallizes in a B2 cubic austenitic structure that transforms into a monoclinic B19? martensitic phase upon cooling. This reversible transformation provides recoverable strains up to 8%, enabling applications requiring both flexibility and precision. Honarvar et al. (2014) demonstrated that critical stresses for phase transformation depend strongly on wire diameter and temperature, with negligible unrecovered strain when heated to 70–80 °C. Öncel and Aç?ma (2024) found that precise control of heat treatment between 540–570 °C optimizes transformation hysteresis and maintains an austenite finish (A_f) temperature below 37 °C, ensuring superelasticity in the human body. Kök and Ate? (2017) studied the effects of elemental substitution (Cr, Cu, Mn, Co, Sn) and observed that minor compositional variations can fine-tune transformation temperatures to match biomedical operating ranges. Additionally, Chaudhari et al. (2021) highlighted the superior fatigue resistance and compatibility of Nitinol for minimally invasive medical devices and MEMS actuators.

Applications and Advantages

Nitinol’s shape memory effect and superelasticity make it a cornerstone of smart engineering design. It is extensively used in medical devices such as stents, guidewires, and orthodontic archwires, where flexibility, strength, and corrosion resistance are critical. In aerospace and robotics, Nitinol is employed in actuators, valves, and vibration dampers. The alloy’s high biocompatibility and nickel-stabilized passive TiO? surface layer prevent cytotoxicity, supporting long-term implantation. Chaudhary et al. (2024) further noted that advancements in microfabrication are expanding Nitinol’s role in MEMS sensors and micro-actuators, combining responsive motion with electrical control in compact designs.

Goodfellow Availability

Goodfellow supplies high-purity Nitinol (Ni55/Ti45) Wire for research, biomedical, and engineering applications. Each wire is precisely heat-treated to maintain reproducible transformation behavior and mechanical performance. Custom diameters, coil geometries, and surface finishes are available to meet specialized design requirements for smart material research and device manufacturing.

Explore Nitinol (Ni55/Ti45) Wire and other advanced materials in Goodfellow’s online catalogue: Goodfellow product finder.

References

• Chaudhary, K., Haribhakta, V. K., & Jadhav, P. V. (2024). A review of shape memory alloys in MEMS devices and biomedical applications. Materials Today: Proceedings. https://doi.org/10.1016/j.matpr.2024.04.105
• Honarvar, M., Datla, N. V., Konh, B., Podder, T., Dicker, A. P., Yu, Y., & Hutapea, P. (2014). Study of unrecovered strain and critical stresses in one-way shape memory Nitinol. Journal of Materials Engineering and Performance, 23(5), 1665–1674. https://doi.org/10.1007/S11665-014-1077-6
• Öncel, L., & Aç?ma, M. E. (2024). Effect of heat treatment conditions on the phase transformation characteristics of Nitinol. Journal of Innovative Engineering and Natural Science. https://doi.org/10.61112/jiens.1484623
• Kök, M., & Ate?, G. (2017). The effect of addition of various elements on properties of NiTi-based shape memory alloys for biomedical applications. European Physical Journal Plus, 132(4), 155. https://doi.org/10.1140/EPJP/I2017-11461-5
• Chaudhari, R., Vora, J. J., & Parikh, D. M. (2021). A review on applications of Nitinol shape memory alloy. In Advances in Intelligent Systems and Computing. Springer. https://doi.org/10.1007/978-981-33-4176-0_10